There has conventionally existed the well-known technology of a network device system such as a service providing apparatus in which a peripheral device (including a copier, a composite machine, a facsimile, a digital camera, a scanner, etc.) is connected to a computer over a network, a service providing system, etc.
For example, with the remarkable progress of communication through the Internet, network-capable equipment has been widely and quickly realized in various types of equipment, including conventional personal computers, user interactive devices such as PDA (Personal Digital Assistants), mobile telephones, etc., image processing devices such as scanners, printers, copying machines, digital cameras, etc., and various domestic electric appliances such as televisions, air conditioners, refrigerators, etc.
In this situation, to enhance the convenience and easiness of using these network-capable devices, various protocols such as automatic setting means for a network address, search and discovery means for a network device, automatic setup means for application software, utility software, an operating system, etc., for control of a network-capable device have been proposed. For example, these include UPnP (registered trademark) mainly developed by Microsoft, BMLinkS (registered trademark) developed by JBMIA (Japan Business Machine Industry Association), Rendezvous (registered trademark) supported by AppleOSX, etc.
On the other hand, various improving means have been applied to reduce the power consumption by these network-capable devices from the energy savings viewpoint. The power consumption of a device driven by a small battery such as a PDA, a mobile telephone, etc., is to be reduced for long-time use. The reduced power consumption is an important factor in the spread of products such as printers, copying machines, thermal fixers, etc., which normally have large power consumption.
Normally, when these devices are not operated for a predetermined period, or are kept in an idle status without performing communication with other devices for a predetermined period, they change into a sleep mode. In the sleep mode, electric power is supplied only to a one-chip microcomputer, a LAN controller, etc., which are low voltage devices, and not to the printer controller of FIG. 1, thereby maintaining the minimal communications capabilities with the power consumption reduced by stopping supply of unnecessary power.
In releasing the sleep mode, these devices monitor traffic for a packet having a specific data format, and when they receive the packet having that specific data format, the sleep mode is released and the normal communications process can be resumed.
Especially, with a rising awareness of earth environmental protection and cost in office and home, there is an increasing demand for more effective power saving systems.
In the above-mentioned UPnP (registered trademark) (UniversalPlugandPlay), a method for detecting a power saving device using a StandbyQuery instruction is disclosed. However, the destination of a Query packet is not disclosed.